Snakes produce venom in special glands on either side of their upper jaw.

Many sea birds have special glands at the base of the bill through which excess salt is excreted.

The caterpillars have special glands that make a sweet liquid called honeydew.

This beetle discharges a very hot fluid from a special gland at potential predators.

Figure 6.4 Pheromones are manufactured and released from special glands.

They do this by rubbing a tiny drop of oil onto every feather from a special gland above the tail.

These components are secreted by special glands located around the eye.

Many animals have special scent glands for leaving these chemical messages.

The main distinguishing feature of mammals is that when they are young their mother feeds them on milk, produced by special glands.

They no longer rely on outside air to fill the bladder, but have special glands for manufacturing gas.